Network traffic prioritization

ABSTRACT

Management of throughput, link rate, airtime, access, collision probability and other factors influencing performance of a wireless access point configured to wirelessly support two or more networks over the same radio channel and/or antenna is contemplated. The management may be suitable for use with access points operating according to a Distributed Coordination Function (DCF) based on Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) whereby each device desiring airtime executes a random binary backoff procedure or other suitable contention based process before attempting to access the channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/150,544, filed Oct. 3, 2018, which application is a continuation ofU.S. patent application Ser. No. 15/288,902, filed Oct. 7, 2016, nowU.S. Pat. No. 10,098,153, which application is a divisional of U.S.patent application Ser. No. 14/537,845 filed Nov. 10, 2014, now U.S.Pat. No. 9,468,020, which claims the benefit of priority to U.S.provisional patent Application No. 62/052,501 filed Sep. 19, 2014. Eachof said patent applications is incorporated in its entirety by referenceherein.

TECHNICAL FIELD

The present invention relates to managing wireless access points, suchas but not necessarily limited to managing throughput, link rate,airtime, access, collision probability and other factors influencingperformance of the wireless access point when configured to wirelesslysupport two or more networks over the same radio channel and/or antennaaccording to the Institute of Electrical and Electronics Engineers(IEEE) 802.11 standards (Wi-Fi).

BACKGROUND

Internet service providers (ISPs) are increasingly offering IEEE 802.11based Wi-Fi services to customers. The proliferation of Wi-Fi enableddevices and the demand for ubiquitous connectivity has driven the ISPsto explore creative ways to increase their service coverage footprint.One approach, referred to as “Community Wi-Fi,” involves the deploymentof customer premise modems (cable, DSL, or fiber) configured forsupporting two or more networks (SSIDs) from a single radio broadcast.Such an arrangement may include one SSID designating a private networkfor the home or business users while the remaining SSIDs are publicnetworks for anyone near the residence or business to use. This approachenables ISPs to leverage their installed equipment base to furtherextend their coverage area with use of a single radio configured to actas multiple virtual access points.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a system having network prioritization in accordanceone non-limiting aspect of the present invention.

FIG. 2 illustrates a community wireless system in accordance with onenon-limiting aspect of the present invention.

FIG. 3 illustrates a schematic for assigning contention windows inaccordance with one non-limiting aspect of the present invention.

FIG. 4 illustrates a flowchart for a method of managing an access pointin accordance with one non-limiting aspect of the present invention.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

FIG. 1 illustrates a system 10 having network prioritization inaccordance one non-limiting aspect of the present invention. The system10 is shown to include an access point 12 configured to facilitatenetwork-based communications between a provider network 14 and a clientnetwork 16. A priority controller 18 may be included to prioritize usageof bandwidth or other resources related to facilitating communicationsbetween the provider network 14 and the client network 16. The providernetwork 14 may relate to any type of network, including a cable network,a hybrid fiber coaxial (HFC) network, a cellular network, an opticalnetwork, a wireless or Wi-Fi network, a wireline network or other typesof network supported by a service provider in multiple system operator(MSO), such as one provided by a television service provider, abroadcast service provider, a satellite service provider, a cellulartelephone service provider, a voice over Internet protocol (VoIP)service provider, an Internet service provider (ISP), etc. The clientnetwork 16 may correspond with a local wireless or wireline networksupported at a location of a subscriber or other access location of thecorresponding service provider.

The client network 16 is shown to be divided into a private network 18and a public network 20. The private network 18 may correspond with ahome network or other network having enhanced security or otherlimitations which require authorization or other consent prior to adevice 22 being granted access. The public network 20 may correspondwith a home network or other network, such as a Wi-Fi hotspot,associated with the same access point 12 but which does not include thesame security or other limitations on devices 24 authorized for access,e.g., the private network 18 may be password protected by the subscriberand the public network 20 may not be password protected or the passwordprotection may be known to roaming partners or devices associated withother subscribers. This type of arrangement may be common where asubscriber/operator desires to support private networking with a firstplurality of users/devices 22 while at the same time supporting publicor community networking with a second plurality of users/devices 24.Such an environment of use may correspond with a wireless network,particularly with a wireless network that supports roaming, sinceroaming or unsecured networks may experience situations in which devices22, 24 are frequently added and removed from the network.

While the public network 20 and the private network 18 are shown to besingular. The networks 18, 20 may be further sub-divided and/or bothnetworks 18, 20 may be private. The use of two private networks 18, 20may be beneficial when the access point 12 is associated with a serviceprovider (not shown) having capabilities to provide wireless or othernetwork access at multiple client locations and/or to support wirelesssignaling with subscribers associated with other service providers,i.e., when a device is roaming between networks. The service provider(s)may provide secure or private access for their own subscribers that roamfrom one of the provider's locations to one associated with anotherservice provider and/or when transitioning to another one of theprovider's other locations. A subscriber of network services may beenabled to access purchased services at another subscriber's locationupon completion of a roaming operation or sign-on operation. U.S. patentapplication Ser. No. 13/423,359, the disclosure of which is herebyincorporated by reference in its entirety, relates to one type ofroaming operation where a device is able to move between subscriberlocations with zero sign-on (ZSO).

The access point 12 is shown to broadcast both of the private and publicnetworks 18, 20 from an antenna or radio interface 30 havingcapabilities sufficient for supporting wireless or wireline signaling. Acable modem 32 or other gateway may include or be operable with theantenna to further facilitate interfacing signaling with the providernetwork 14, such as in the manner described in U.S. patent applicationSer. No. 13/652,700, the disclosure of which is hereby incorporated byreference in its entirety herein. The antenna 30 may be configured tointerface signaling between the various devices 22, 24 and the cablemodem 32. The antenna 30 may include one aerial, as shown, or multipleaerials and/or antenna elements, including configurations suitable tofacilitating Multiple-Input Multiple-Output (MIMO) communications, suchas that associated with U.S. patent application Ser. Nos. 14/181,640,14/181,641, 14/181,643 and 14/181,645, the disclosures of which arehereby incorporated by reference in their entireties herein. Onenon-limiting aspect of the present invention contemplates the antenna 30or additional antennas optionally being required to share availableupstream and/or downstream bandwidth with the networks 18, 20 over thesame frequency. While the present invention applies equally to multipleantenna configurations or access points 12 having other configurationswhere multiple devices may be enabled to communicate with the providernetwork 14 at the same time, the illustrated environment is particularlycontemplated since it presents a problem where a plurality of userdevices 22, 24 share a common radio interface or baseband processor,i.e. a common resource governed by a contention based access method,such as in the manner described in CableLabs Wireless Specifications,Wi-Fi Requirements For Cable Modem Gateways, WR-SP-WiFi-GW-I02-120216,the disclosure of which is hereby incorporated by reference in itsentirety.

The priority controller 18 may be configured to facilitate prioritizingconsumption of network resources according to characteristics of thedevices 22, 24 and/or the private and public networks 18, 20. Theconsumption of network resources is predominately described with respectto consumption of upstream bandwidth as there may be sufficientdownstream bandwidth to support simultaneously communicating withmultiple devices. The upstream bandwidth may correspond with an upstreampath defined from the access point 12 to the provider network 14 and/ora path defined from the devices 22, 24 to the access point 12. As iscommon in HFC and other systems where greater volumes of traffic arecarried in a downstream direction, a greater amount of bandwidth may beallocated for downstream communications, i.e. in a direction from theprovider network 14 to the client network 16, than that which isallocated for upstream communications, i.e. in a direction from theclient network to the provider network. The present invention, however,applies equally to prioritizing communications in either one of theupstream and downstream directions, and as such, the present inventionis not necessarily limited to prioritizing upstream communications. Thepriority controller 18 is shown to be a standalone entity but it may beincluded as part of the access point 12 and/or a device of the providernetwork 14 or client network 16.

The priority controller 18 may include a non-transitorycomputer-readable medium having non-transitory instructions operable tofacilitate controlling the access point 12 and/or the devices 22, 24 toimplement the network prioritization contemplated in U.S. patentapplication Ser. No. 13/537,707, the disclosure of which is herebyincorporated by reference in its entirety herein and in the mannerdescribed below in more detail. One non-limiting aspect of the presentinvention contemplates implementing the network prioritization tofacilitate managing throughput, link rate, airtime, access, collisionprobability and other factors influencing performance for the wirelessaccess point 12 when operating according to the Institute of Electricaland Electronics Engineers (IEEE) 802.11 standards (Wi-Fi), such as inaccordance with Part 11: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY) specifications: Medium Access Control (MAC) Qualityof Service Enhancements, the disclosure of which is hereby incorporatedby reference in its entirety herein. The present invention is notnecessarily limited to Wi-Fi and is equally application with otherwireless networking, including those capable of engaging DistributedCoordination Function (DCF) based on Carrier Sense Multiple Access withCollision Avoidance (CSMA/CA) whereby each device 22, 24 desiringairtime executes a random binary backoff procedure before attempting toaccess a shared channel.

Internet service providers (ISPs) are increasingly offering IEEE 802.11based Wi-Fi services to customers. The present invention contemplatesleveraging the proliferation of Wi-Fi enabled devices and the demand forubiquitous connectivity to increase ISP service coverage footprint.Since essentially all wireless transmissions are subject to free spacepath loss, the path loss (also known as isotropic spreading loss)represents the most basic and fundamental transmission loss model. Thefree space loss of an isotropic radiator may be given by equation (1)shown below:

${{Free}{SpacePathLoss}} = {{20 \star {{Log}\left( \frac{4\pi d}{\lambda} \right)}} = {20 \star {{Log}\left( \frac{4\pi{df}}{c} \right)}}}$

where d is distance in meters, λ is wavelength in meters, f is frequencyin Hz and c is speed of light in meters per second.

In the community Wi-Fi use case, the distance between the transmitterand the receiver will generally be less than 100 feet. Because of this,the Free Space Loss equation above will suffice as a first orderapproximation of the propagation characteristics for outdoor users.Table 1 below shows an exemplary free space loss at 2.4 and 5 GHz.

2.4 GHZ 5 GHZ DISTANCE DISTANCE LOSS LOSS (FEET) (METERS) (DB) (DB) 3.31 40.0 46.4 6.6 2 46.1 52.4 13.2 4 52.1 58.5 26.4 8.1 58.1 64.5 32.8 1060.0 66.4 65.6 20 66.1 72.4 131.2 40 72.1 78.5 196.8 60 75.6 82.0 328100 78.1 84.5

For indoor users, one signal propagation model may be the ITU indoormodel (ITU-R RECOMMENDATION P.1238-7, Propagation data and predictionmethods for the planning of indoor radio communication systems and radiolocal area networks in the frequency range 900 MHz to 100 GHz, 2012).This propagation model was developed for a frequency range that includesthe 2.4 GHz and 5 GHz bands, and based on this model, propagation lossmay be given by equation (2) shown below:L _(total)=20*log₁₀(f)+N*log₁₀(d)+L _(f)(n)−28

where Ltotal is loss in dB, f is frequency in MHz, N is the distanceloss coefficient, d is distance from the access point (AP) to the clientin meters, and Lf (n) is the floor loss penetration factor for n floors.In this model, the loss due to wall penetration and in room objects maybe included in the distance loss coefficient. For residentialconstruction, i.e. wood wall structure, the distance loss coefficientmay be given as 28. Table 2 below shows the indoor propagation lossgiven by (2) assuming a single level (n=0) home/system 40 similar toFIG. 2.

2.4 GHZ 5 GHZ DISTANCE DISTANCE LOSS LOSS (FEET) (METERS) (DB) (DB) 3.31 39.6 47.3 6.6 2 48.0 55.7 13.2 4 56.5 64.1 26.4 8 64.9 72.6 32.8 1067.6 75.3

One contemplated way to predict wireless coverage area is using a linkbudget model. In such a model, all power gains and losses are accountedfor between the transmitter and the receiver. The resulting modelpredicts the maximum propagation loss tolerated by a functioningwireless link. For a Wi-Fi client, one possible link budget model isgiven by equation (3) shown below:LinkLoss_(total) =P _(tx) +G _(tx) +L _(tx) +G _(rx) +L _(rx) −P _(rx)+L _(m)

where LinkLosstotal is the maximum tolerated propagation loss, Ptx isthe AP transmit power, Gtx is the transmitter antenna gain, Ltx is thetransmitter loss, Grx is the receiver antenna gain, Lrx is the receiverloss, Prx is the receiver minimum sensitivity of the client, and Lm ismiscellaneous loss. (All values are in dB.) The maximum link budget of acommon Wi-Fi link is approximately 110 dB from Tx chip to Rx chip. Thisis based on the following assumptions:

-   -   1. Both the transmitter and the receiver are using        omnidirectional antennas with 1 dB gain.    -   2. The transmitter is transmitting at 20 dBm.    -   3. The receiver minimum threshold is −88 dBm.    -   4. Transmitter and receiver losses are zero (ideal).    -   5. Miscellaneous loss is zero (ideal).

The above is based on the assumptions that are in some cases idealized.Regardless, it is clear that in the application of the Community Wi-Fiuse case in a residential or small business setting, a large portion ofusers at the sidewalk or in the street will be at the edge of thecoverage area for an indoor AP. In general, clients at the coverage areaedge use a lower physical layer data rate than clients closer to the AP.

A fundamental problem in wireless communication is controlling access tothe shared medium/channel. The media access control (MAC) layer definesthe rules and procedures for channel access of a given protocol. Wi-Fi,as defined by the 802.11-working group of the Institute of Electricaland Electronic Engineers (IEEE), uses an access method called theDistributed Coordination Function (DCF). The design of the DCF is basedon Carrier Sense Multiple Access with Collision Avoidance or CSMA/CA. Inthe DCF system, each device uses the following three basic steps whenattempting to access the shared medium:

1. Perform a Clear Channel Assessment (CCA) by sensing the medium for aperiod of time before attempting to transmit. If the device determinesthat the medium is clear it proceeds to the next step.

2. Check the Network Allocation Vector (NAV), the virtual CCA mechanism,to ensure no hidden nodes are currently using the channel.

3. If the device determines the channel is busy in step 1 or 2, it setsa binary exponential backoff timer and waits before attempting theaccess the medium again, starting back at step 1. Otherwise, if thedevice senses the medium is not busy, the device can now transmit aframe.

For most traffic types, the amount of time the device must sense themedium in step one is the sum of the appropriate Interframe Space (IFS)plus the random binary back-off time called the Contention Window (CW).The IFS most often used is called the DCF IFS or DIFS. This may be afixed parameter determined by the physical layer characteristics of thenetwork. The DIFS is defined as 2×Slot Time+SIFS. In a few select casesthe device may use a short IFS, or SIFS, to access the channel withoutadding the CW. This medium access method gives certain packets absolutepriority access to the medium over those using the DIFS+CW method. Thesespecial cases include layer 2 acknowledgements, the response message toa Request-To-Send (RTS) frame called the Clear-to-Send (CTS) frame, dataframes immediately following a CTS message, and any fragments of afragmented frame after the first portion has been sent. There is a thirdIFS defined in the base 802.11 standards called the PCF IFS. However,Point Coordination Function (PCF) operation has seen little, if any,adoption so neither it, nor the PIFS will be discussed further.

Table 3 below provides a summary of the various IFS values.

2.4 GHz 5 GHz Phy 802.11 b 802.11 g 802.11 n 802.11 a 802.11 n Slot 20us Long GI = Long GI =  9 us  9 us Time 20 us 20 us Short GI = Short GI=  9 us  9 us SIFS 10 us 10 us 10 us 16 us 16 us DIFS 50 us Long GI =Long GI = 34 us 34 us 50 us 50 us Short GI = Short GI = 28 us 28 us

When devices on the network attempt to gain access to the channel, theyuse a random binary back-off procedure. In this procedure, during thefirst attempt to access the channel, a random value between zero and thecontention window minimum value (CWmin) is chosen. In this fashion, theprobability of collisions is reduced via each device choosing a randomback-off value from a range. FIG. 3 illustrates a schematic 44 forassigning contention windows in accordance with one non-limiting aspectof the present invention.

Air interface packet collisions are detected by the absence of a layer-2acknowledgement frame from the receiving party in response to atransmitted frame. Increasing the size of CWmin (content window) canincrease the channel access latency, but it also reduces the probabilityof a collision. The contention window random backoff process is thebasis of one non-limiting aspect of the present invention describedbelow in more detail whereby the size of the CWmin maybe dynamicallyadjusted one a per device (e.g., devise 22, 24) or per network (e.g.,networks 18, 20) basis to manage airtime as a function of metricsrepresenting network conditions. In the Community Wi-Fi use case, theprivate network 18, servicing the home users, may want priority accessto ensure compliance with a Service Level Agreement (SLA), eitherexplicit or implicit, between the customer and the service provider. Insuch a scenario, one non-limiting aspect of the present inventioncontemplates ensuring that resources are first allocated to the privatenetwork 18 and any resources in excess of those needed to meet the SLAcan then be allocated to the public network 20.

In Wi-Fi networks, throughput, though the primary interest of the user,may not be a good performance metric due to the large number ofvariables which effect single client and aggregate network throughput.For many instances, a metric called airtime is a better indicator ofrelative network resource allocation between a set of clients. Airtime,for the exemplary purposes described herein, may be the amount of timeover a fixed interval that a given client has access to transmit on theshared channel. The relationship between user level throughput andairtime is upper-bounded and may be represented as in equation (4) shownbelow:

$R_{client} \leq {R_{phy} \star \frac{1}{n} \star \frac{{Airtime}_{client}}{{Airtime}_{total}}}$

where Rclient is user throughput data rate, Rphy is the physical layerlink data rate. The factor n is to account for the time needed by theDIFS, SIFS, and by the receiving node to send an acknowledgement frame.This scaling factor varies depending on the spectrum band used andversion of 802.11 (e.g. 0.11 a, 0.11 b, 0.11 g, etc) and takes a valuein the range 1≤n≤2. It can be easily seen from (4) that user levelthroughput is directly proportional to the airtime that a clientreceives.

The airtime needed to transmit a packet of Bpkt bytes of data may begiven by equation (5) shown below:

${Airtime}_{pkt}\overset{\bigtriangleup}{=}{T_{DIFS} + \frac{B_{pkt}}{R_{phy}} + T_{SIFS} + T_{ack}}$

where Tdifs accounts for the time from DIFS, Tsifs is the time for aSIFS, and Tack accounts for the time needed to send the acknowledgementframe. From (5) it can be seen that the airtime needed to transmit apacket is inversely proportional physical layer data rate Rphy. Asmentioned previously, clients farther from the AP will use lowerphysical layer data rates. Therefore, by combining the fair channelaccess of the DCF, with equations (4) and (5), clients at the edge ofthe network coverage area will use more airtime while getting lowerthroughput due to less efficient use of the airtime. As others haveshown, the total network throughput may be upper bounded by thereciprocal of the harmonic mean of the physical layer data rates of then clients on the network, as shown in equation (6) below.

$R_{tot} \leq \frac{1}{\frac{1}{n}{\sum\limits_{i = 1}^{n}\frac{1}{R_{phyi}}}} \leq {n \star {\frac{\min}{1 \leq i \leq n}R_{phyi}}}$

Applying this concept to the Community Wi-Fi use contemplated herein itis clear that with a single radio AP the public network users, who willpredominantly be farther from the access point than the private network20, will undoubtedly have a negative effect on the overall networkthroughput, and therefore the private network 18 throughput. Onenon-limiting aspect of the present invention contemplates a controlalgorithm that resolves uncontrolled resource allocation problem in thecommunity Wi-Fi use case, such as but not necessarily limited to thatdescribed above where users farther from the access point 30 governthroughput. The proposed algorithm leverages the CWmin, the client countratio between the networks, and the physical layer data rates of theclients within each network to manage airtime and strike a balancebetween access and prioritized throughput.

The contemplated airtime management may leverage capabilities availableaccording to the CWmin adaptation support provided in many Wi-Fi devicesaccording to IEEE 802.11e, the disclosure of which is herebyincorporated by reference in its entirety herein. In the exemplaryCommunity Wi-Fi configuration, the present invention may manage airresource such that throughput thresholds are protected for the privatenetwork 18. Any air resources in excess of those needed to achieve theprivate network 18 throughput threshold can be then shared with thepublic network(s) 20 to provide service to roaming customers, etc. Inthis scenario, the networks 18, 20 are being managed as opposed to anysingle client. The number of private clients active at any given timemay affect the resources being used by the networks 18, 20, and as such,the contemplated CWmin adaptation process may account for a varyingclient count ratio so that the appropriate per client channel accessprobability is assigned and the overall network channel access ratio ismaintained. The contemplated management may be dynamic to account forscenarios such as active clients going into power save mode for longperiods (inactive) or clients joining and leaving the network.

Airtime is directly proportional to both channel access probability aswell as the physical layer link rate of the client(s) 22, 24. Since lowrate clients govern the throughput behavior of a network, the presentinvention also contemplates controlling throughput or airtime,

${{CW}\min_{pub}} = {{{CW}\min_{priv}} + \left\lceil {\log_{2}\left( {\frac{n \star R_{desired}}{R_{\min}} \star \frac{{Count}_{pub}}{{Count}_{priv}}} \right)} \right\rceil}$or both, with consideration of the physical layer link rate, e.g., theminimum link rate for devices 22, 24 in both networks 18, 20 may becompared to the object throughput rate when used for determining theCWmin of the public network 20. The CWmin adaptation algorithm proposedherein to accomplish these objectives may be designed to protect apredetermined throughput threshold for the private network 18. Thealgorithm may be designed to use the CWmin of the private network 18(CWminpriv) as a baseline. The CWmin for the public network 20(CWminpub) may then be scaled based on the physical layer link rateratio and the client count ratio to provide a probability of channelaccess success ratio for the private network 20 that is sufficient toachieve the desired data rate. The scaling function may correspondingwith equation (7) shown below as:

Where desired is the desired throughput of the private network, n is ascaling function defined for each physical layer and accounts forprotocol overhead (e.g. n=2 for 802.11g), Rmin is the minimum physicallayer link rate of any active client 22, 24 in either network 18, 20,and Countpriv and Countpub are the active client counts in the privateand public networks 18, 20, respectively. The active clients may bethose actively attempting to gain access, those connected to one of thenetworks 18, 20 and/or those not in a sleep mode or otherwise not likelyto consume services. The log base two function is used find theappropriate value for use with the current definition of CWmin with theceiling function being used to always round up so that the threshold isprotected absolutely.

The control algorithm in the contemplated implementation, may berepresented in pseudocode as follows:

If (Active Client Count in Private>0 && Active Client Count inPublic>0), Update CWminpub per equation (7)

Else Use default CWminpub=5

End

In this way, when any network is the only network with an active client,a static DCF configuration maybe used, e.g., the CWminpriv and CWminpubmay be set to a design value and kept there until a device becomesactive on both networks 18, 20. However, when both networks have clientsthat are actively contending the channel, the relative channel accessprobability is governed by (7) to ensure the private network 18 receivesthe necessary resources for the desired throughput rate, e.g., CWminprivmay be fixed and CWminpub may be dynamically adjusted based on variousmetrics/ratios.

The proposed algorithm and proof of concept implementation described inthe provisional application incorporated by reference herein provideevidence that the contemplated management may be capable of addressingthe resource protection goal of Community Wi-Fi implementations.However, during the development and testing phases, areas of futureoptimization were identified. First, the inability to use integer stepsizes, at least for IEEE 802.11e, for CWmin adjustments may be ahindrance to the optimal tuning of the parameter. For the proof ofconcept implementation the ceiling function was used to ensuresufficient priority for the private network. However, an alternativeapproach is to use dithering to rapidly modulate the CWmin value toachieve and effective CWmin that is between the power of two stepscurrently available. The second optimization may be to tune the controlprocess with some measure of hysteresis such that rapid fluctuations inphysical layer link rate were smoothed from the viewpoint of (7). Such asmoothing process may provide a more stable CWmin for the public network20.

FIG. 4 illustrates a flowchart 50 for a method of managing an accesspoint in accordance with one non-limiting aspect of the presentinvention. The method is predominately described for exemplarynon-limiting purposes with respect to managing a wireless access pointconfigured to simultaneously support wireless signaling for two network(e.g. public and private networks) over the same radiofrequency/channel. This is done without necessarily intending to limitthe scope and contemplation of the present invention as the managementcontemplated herein may be similarly used to facilitate managing threeor more networks over the same radio frequency/channel. The method isalso predominantly described for exemplary, non-limiting purposes withrespect to a contention-based process where devices attempting to accessairtime over either one of the public and private networks are requiredto execute a backoff procedure prior to attempting to access thechannel. The backoff procedure may be characterized by each deviceattempting to access the channel during a backoff slot selected,optionally randomly, from a plurality of backoff slots defined in acorresponding contention window, such as but not necessarily limited tothe manner described in the specifications associated with IEEE 802.11.

Block 52 relates to determining an SSID for each of the networks sharingthe radio channel. The SSID may be broadcasted from the access point andcorrespondingly ascertained by the devices, such as when authenticatingor otherwise engaging operations necessary to connect with the accesspoint. The access point may include a table or other listing of SSIDsassociated with a particular one or more of its antennas or antennaselements, e.g., the wireless access point may be configured to supportmultiple community-Wi-Fi implementations over the same antenna oradditional antennas where each network grouping shares differentchannels (e.g., one set of private and public networks at a firstfrequency and another set of public and private networks at a secondfrequency). The access point may also list in the table or otherwisetrack the devices connected to or associated with each SSID so as toidentify each device (MAC, IP address, etc.) as well as whether thedevice is currently active or inactive. The wireless access point isuniquely positioned to assess characteristics and other metricsregarding the devices connected thereto that the devices themselves maynot be able to ascertain, such as the SSID utilized by each devicesimilarly associated with the access point.

Block 54 relates to determining counts sufficient for representing thenumber of for devices actively connected to each of the SSIDs. Thecounts may represent the number of devices contending for airtime orother resources via the shared channel. In some cases, a device may beconnected to the access point but not otherwise attempting to consumeresources, such as if the device is sleeping or otherwise inactive for along period of time, and the counts may consider such operatingconditions when counting or not counting a device. The counts may be oneof the metrics known to the access point and unknown to the connecteddevices contemplated for use with the present invention in facilitatingmanagement of the shared channel. In the exemplary scenario a Countprivmay indicate the number of devices connected to the private network anda Countpub may indicate the number devices connected to the publicnetwork. The access point may continuously track the counts for eachnetwork on a regular basis, such as every few seconds or minutes, and/orwhen other events occur, such as when devices newly connected to orleave the one of networks.

Block 56 relates to determining rates for representing desired and/oractual data throughput between the access point and the devices. EachSSID may be assigned a desired throughput, e.g., the private network maybe assigned a higher throughput than the public network and or viceversa, as a design parameter intended to represent desired operation ofthe access point. A link rate or other throughput measure may also bedetermined to measure data rates actually being achieved between theaccess point and each of the devices. The link rate, as noted above, caninfluence overall system performance in achieving the desiredthroughput, particularly when devices are connected to an edge of theshared radio channel. While the present invention fully contemplatesmaintaining desired throughputs for one or more public networks, thisexemplary description contemplates a use case where the public networkis given best efforts while attempting to maintain the private networkas close to a desired throughput (Rdesired) as possible. A throughput ofeach device, regardless of whether the devices are connected to thepublic or private network, may be measured and the link rate of aslowest one of the devices may be determined as Rmin. Rdesired Rmin maybe metrics known to the access point and unknown to the devices (thedevices may know their own link rate but not that of the other devices).

Block 58 relates to determining contention windows (backoff slots) orother mechanism suitable to controlling access for each of the networkssharing the radio channel. The contention window assigned to each devicemay be determined based on the metrics noted above and desiredoperational consideration to manage the probability of each devicegaining network access in manner sufficient to achieve the desiredoperation of the private network and best efforts for the publicnetwork. The contention windows may be allocated on a per-S SID basissuch that the same contention window is used for each device connectedto the same SSID. The ability to implement SSID-based assignment of thecontention windows may be beneficial in enabling adjustments to becontinuously made to one network without having to adjust both networks,e.g., the private network contention window (CWminpriv) can be fixed andthe public network contention window (CWminpub) can be continuouslyadjusted in order to maintain the public network at desired operationlevels. One non-limiting aspect of the present invention contemplatessetting/fixing the CWminpriv and scaling the CWminpub according to ascaling function or other operand according to measured/known metrics inorder to achieved the desired operation of the private network.

The CWminpub may be dynamically scaled according to the CWminpriv as afunction of the Rdesired and the Rmin such that the CWminpub increaseswhen the slowest link rate decreases in proportion to the throughput andsuch that the CWminpub decreases when the slowest link rate increases inproportion to the throughput. The CWminpub may be dynamically scaledaccording the CWminpriv as a function of the Countpub and the Countpubsuch that the CWminpub increases when the Countpub increases relative toCountpriv and such that the CWminpub decreases when the Countpubdecreases relative to the Countpriv. FIG. 3 illustrates a scenario wherethe CWminpriv is less than or shorter than the CWminpub for exemplarynon-limiting purposes as it may be desirable to keep CWminpriv less thanCWminpub when a certain number of devices are connected each of thecorresponding SSIDs. The CWminpriv need not necessarily be shorter thanthe CWminpub, such as when the number of devices connected to thecorresponding SSIDs and/or the rates associated there with aresufficiently skewed such that desired performance of the private SSIDmaybe be achieved even when the CWminpub is less than the CWminpriv.

The rate and count based scaling may optionally be combined according tothe scaling function shown below in order to accommodate each metric inthe scaling of CWminpub.

${{CW}\min_{pub}} = {{{CW}\min_{priv}} + \left\lceil {\log_{2}\left( {\frac{n \star R_{desired}}{R_{\min}} \star \frac{{Count}_{pub}}{{Count}_{priv}}} \right)} \right\rceil}$

The CWminpriv value is described above as being fixed and/or setaccording to a desired value and thereafter scaled according to metricsrepresentative network conditions in order to calculate an appropriateCWminpub. The CWminpriv is not necessarily required to be fixedthroughout operation and may be varied over time for any number ofreasons, including when throughput or other performance requirements ofthe private network change, such as when the private network iscontrolled to provide different levels of QoS depending on traffic,subscriptions, services, etc. The access point may be configured toadjust the metrics as desired to change how resources are managed forthe shared channel. The results calculated for CWminpub may be limiteddue to mathematical operands such that only certain integer values areachievable such that It may be desirable in some cases to calculate orachieve a CWminpub public between these integer values and/or to smoothtransitions when switching from one CWminpub value to another CWminpubof value. Accordingly, the present invention contemplates ditheringbetween two integer values for CWminpub by rapidly switching between thetwo integer values to produce the effect of a non-integer intermediatevalue and smoothing a transition between two integer values for CWminpubby gradually increasing or decreasing the CWminpub when transitioningbetween the two integer values such that the CWminpub is at least set toone intermediary value before being set to one of the two integer values

While the foregoing describes a two-network configuration, similarmethodology may be performed for scaling CWminpub for multiple publicnetworks relative to a desired CWminpriv. The following scaling functionmay be implement with three or more networks (N networks) where a mthcontention window for devices associated with an mth SSID (m equals {1,2, . . . , N}) deemed as the private network is fixed.

${{CW}\min_{m + 1}} = {{{CW}\min_{m}} + \left\lceil {\log_{2}\left( {\frac{n \star R_{desired}}{R_{\min}} \star \frac{{Count}_{m + 1}}{\sum\limits_{i = 1}^{N}{Count}_{i}}} \right)} \right\rceil}$

wherein CWmin_(m+1) is the m+1^(th) contention window, CWmin_(m) is them^(th) contention window, Rdesired is desired throughput for the accesspoint, Rmin is a slowest link rate for any device actively associatedwith any one of the mth SSIDs, Countp_(m) is a count of active devicesassociated with the mth SSID, Count_(m+1) is a count of active devicesassociated with the m+1^(th) SSID and n is a scaling value.

One non-limiting aspect of the present invention contemplates a Wi-FiUplink QoS Control Algorithm via CWmin Adaptation where, in theCommunity Wi-Fi use case where there is a private and public SSID areserved via a single Wi-Fi radio, uplink resource management iscontrolled. By controlling the CWmin value of the public SSID relativeto the private SSID, the probability of success when attempting to gainaccess to the shared channel can be controlled to achieve the desiredperformance for the private SSID.

One non-limiting aspect of the present contemplates a Wi-Fi NetworkReal-Time Throughput Estimation where an algorithm for predicting orestimating an upper bound on a Wi-Fi networks aggregate throughput basedon information available to the AP is monitored. As Wi-Fi APs aredeployed with the intention of supporting more services (Voice, Video,public and private data, security, IoT) the need for bettertroubleshooting tools increases greatly. This present inventioncontemplates a method to predict or estimate an upper bound on theavailable Wi-Fi throughput based on client count and the physical layerdata rate of each client for the purposed of implementing correspondingcontrol of CWminpub and CWminpriv. The contemplated estimation methodmay be used to provide an upper bound to the network throughput when allstations have full buffer traffic loads i.e. saturation conditions.Alternatively the estimate can be weighted based on traffic load data(or assumptions) for each client in the network.

One non-limiting aspect of the present contemplates a Service AwareWi-Fi QoS for Community Wi-Fi where a Wi-Fi air interface QoS mechanismuses a priori knowledge of device-to-service mappings to adjust targetthroughput it is protecting for the private SSID in the Community Wi-Fiuse case. This dynamic method allows the algorithm to ensure good userexperiences for highly leveraged Wi-Fi networks operating on a singleradio.

The foregoing concepts include capabilities for estimating Wi-Fi networkthroughput in real time and also a dynamic QoS function that uses staticthresholds. This invention takes user input or smart deviceidentification to determine the throughput threshold to protect via themethod described above (CWmin adaptation). Consider a case where asubscriber has data and video services utilizing the Wi-Fi interface.The subscriber may have 2 wireless TVs and 2 data usage devices. Thealgorithm would assign a target data rate to each device. When eachdevice became active on the network, the QoS rate control algorithmwould appropriately adjust the target data rate it was protecting, thuseffecting the CWmin adaptation algorithm to accordingly de-prioritizepublic SSID user traffic. In this way the QoS mechanism on the airinterface would become service aware and vary its level of protectionfor the private service set based on real time usage needs. This dynamicmethod prevents overly defensive settings from harming the public userexperience when the private user devices are dormant, and ensures a gooduser experience for the private user when they are using their MSOoffered services.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

What is claimed is:
 1. A method for managing a wireless communicationsystem, comprising: supporting a first network and a second network froma common radio channel, the first network having a first minimumcontention window associated therewith, and the second network having asecond minimum contention window associated therewith, the secondminimum contention window associated with the second network being afunction of, but different from, the first minimum contention windowassociated with the first network; and adjusting the second minimumcontention window according to one or more parameters of the wirelesscommunication system, while leaving the first minimum contention windowunchanged, to control access to the common radio channel to achieve atleast a predetermined minimum performance of the first network.
 2. Themethod of claim 1, wherein to control access to the common radio channelcomprises limiting consumption of network resources by one or moredevices of the second network.
 3. The method of claim 1, the first andsecond networks sharing a common access point.
 4. The method of claim 1,the first and second networks sharing a common antenna.
 5. The method ofclaim 4, the common antenna comprising a plurality of antenna elements.6. The method of claim 1, the first and second networks sharing a commonradio interface.
 7. The method of claim 1, the first and second networkssharing a common baseband processor.
 8. The method of claim 1, whereinthe second minimum contention window is greater than the first minimumcontention window.
 9. The method of claim 1, wherein the second minimumcontention window is less than the first minimum contention window. 10.The method of claim 1, wherein adjusting the second minimum contentionwindow according to one or more parameters of the wireless communicationsystem comprises adjusting the second minimum contention window at leastpartially based on a number of clients connected to the second network.11. The method of claim 1, wherein adjusting the second minimumcontention window according to one or more parameters of the wirelesscommunication system comprises adjusting the second minimum contentionwindow at least partially based on each of (a) a number of clientsconnected to the first network and (b) a number of clients connected tothe second network.
 12. The method of claim 1, wherein adjusting thesecond minimum contention window according to one or more parameters ofthe wireless communication system comprises adjusting the second minimumcontention window at least partially based on a minimum physical datalink rate of any active client.
 13. The method of claim 1, whereinadjusting the second minimum contention window according to one or moreparameters of the wireless communication system comprises adjusting thesecond minimum contention window at least partially based on (a) aminimum physical data link rate of any active client and (b) a desiredphysical data link rate.
 14. The method of claim 1, further comprisingsetting the second minimum contention window to a static value inresponse to one of the first and second networks being a sole network inthe wireless communication system having an active client.
 15. Themethod of claim 1, further comprising modulating the second minimumcontention window between two values.
 16. The method of claim 1, furthercomprising maintaining the first minimum contention window at a fixedvalue.
 17. The method of claim 1, wherein: the first minimum contentionwindow is used with all devices connected to the first network; and thesecond minimum contention window is used with all devices connected tothe second network.
 18. The method of claim 1, wherein: the firstminimum contention window is used with only one device of a plurality ofdevices connected to the first network; and the second minimumcontention window is used with only one device of a plurality of devicesconnected to the second network.
 19. The method of claim 1, whereinadjusting the second minimum contention window according to one or moreparameters of the wireless communication system comprises scaling thesecond minimum contention window at least partially as a function of thefirst minimum contention window.
 20. The method of claim 1, furthercomprising changing the first minimum contention window in response to achange in a parameter associated with the first network.
 21. A methodfor managing a wireless communication system, comprising supporting afirst network and a second network from a common radio channel, thefirst network having a first minimum contention window associatedtherewith, and the second network having a second minimum contentionwindow associated therewith; adjusting the second minimum contentionwindow according to one or more parameters of the wireless communicationsystem, while leaving the first minimum contention window unchanged, tocontrol access to the common radio channel; supporting a third networkfrom the common radio channel, the third network having a third minimumcontention window associated therewith; and adjusting the third minimumcontention window according to one or more parameters of the wirelesscommunication system, while leaving the first minimum contention windowunchanged, to limit consumption of network resources by one or moredevices of the third network.
 22. A method for prioritizing networktraffic on a single channel of a wireless access point, comprising: at adevice of a first network, performing a first clear channel assessment(CCA) of the single channel for at least a first period of timeassociated with the first network; in response to the first CCAindicating that the single channel is not busy, wirelessly transmittingdata between the device of the first network and the wireless accesspoint; at a device of a second network, performing a second CCA of thesingle channel for at least a second period of time associated with thesecond network; in response to the second CCA indicating that thechannel is not busy, wirelessly transmitting data between the device ofthe second network and the wireless access point; and adjusting thesecond period of time associated with the second network as a functionof the first period of time associated with the first network to achieveat least a predetermined minimum performance of the first network.